Low profile rear derailleur with cable guide

ABSTRACT

A bicycle rear derailleur comprises a base member; a movable member that supports a chain guide including a first pulley that rotates around a first pulley axis, wherein the pulley has a pulley plane; a first linking member coupled between the base member and the movable member so that the chain guide moves laterally relative to the base member between a first lateral position and a second lateral position, and a cable guide supported to the base member to guide a shift control cable. The pulley plane intersects the first linking member when the chain guide is located at a first position between the first lateral position and the second lateral position.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of copending application Ser.No. 11/307,941, filed Feb. 28, 2006.

BACKGROUND OF THE INVENTION

The present invention is directed to bicycles and, more particularly, toa low profile rear derailleur used to switch a chain among a pluralityof sprockets that rotate with the rear wheel.

A bicycle rear derailleur is used to selectively engage a chain with oneof a plurality of sprockets that rotate with the rear wheel of thebicycle. A typical rear derailleur comprises a base member, a movablemember supporting a chain guide, and a linking mechanism coupled betweenthe base member and the movable member so that the chain guide moveslaterally relative to the base member. The base member usually ismounted to the rear end of the bicycle frame by a mounting bolt thatscrews into a threaded opening formed in the frame. Because of thenature of the lateral movement of the chain guide required to switch thechain among the sprockets, the linking mechanism, the movable member andthe chain guide all protrude laterally outward by a significantdistance, especially when the chain is engaged with the laterallyoutermost rear sprocket. As a result, the chain guide is susceptible tostriking or becoming entangled with nearby objects, especially whenriding off-road in mountainous terrain. The effect becomes more severeas the number of sprockets increase.

SUMMARY OF THE INVENTION

The present invention is directed to various features of a bicycle rearderailleur. In one embodiment, a bicycle rear derailleur comprises abase member; a movable member that supports a chain guide including afirst pulley that rotates around a first pulley axis, wherein the pulleyhas a pulley plane; a first linking member coupled between the basemember and the movable member so that the chain guide moves laterallyrelative to the base member between a first lateral position and asecond lateral position, and a cable guide supported to the base memberto guide a shift control cable. The pulley plane intersects the firstlinking member when the chain guide is located at a first positionbetween the first lateral position and the second lateral position.Additional inventive features will become apparent from the descriptionbelow, and such features alone or in combination with the above featuresmay form the basis of further inventions as recited in the claims andtheir equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a laterally outer view of a particular embodiment of a rearderailleur in a high speed position;

FIG. 2 is a laterally inner view of the derailleur;

FIG. 3 is a top view of the derailleur in the high speed position;

FIG. 4 is a bottom view of the derailleur in the high speed position;

FIG. 5 is a front view of the derailleur in the high speed position;

FIG. 6 is a rear view of the derailleur in the high speed position;

FIG. 7 is a side view of the derailleur in a low speed position;

FIG. 8 is a top view of the derailleur in the low speed position;

FIG. 9 is a bottom view of the derailleur in the low speed position;

FIG. 10 is a front view of the derailleur in the low speed position;

FIG. 11 is a rear view of the derailleur in the low speed position; and

FIG. 12 is a laterally outer view of the rear derailleur attached to aconventional frame;

FIG. 13 is a laterally outer view of another embodiment of a rearderailleur attached to a conventional frame;

FIG. 14 is a more detailed view of the base member and cable guide;

FIG. 15 is a view taken along line 15-15 in FIG. 14;

FIG. 16 is a rear elevational view of the derailleur mounting boss; and

FIG. 17 is a rear elevational view of the base member.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIGS. 1-11 are various views of a particular embodiment of a low profilederailleur 10 in various positions. For example, FIG. 1 is a laterallyouter view of rear derailleur 10, and FIG. 2 is a rear view ofderailleur 10. As shown in FIG. 1, rear derailleur 10 is attached to therear portion of a bicycle frame 14 for guiding a chain 18 among aplurality of rear sprockets R1-R8 that rotate coaxially around a rearwheel axle 22 supported to frame 14, wherein axle 22 defines arotational axis X. As used herein, including the claims, the terms up,down, front, rear, laterally inward and laterally outward refer to theorientation of a derailleur as if it were attached in its normaloperating position to an upstanding bicycle as shown in FIG. 1, forexample, wherein the front of the derailleur is the right portion of thederailleur shown in FIG. 1. The terms left and right refer to thelateral sides of the derailleur when viewed from the rear as shown inFIG. 3. The term laterally inward refers to the side of the derailleurthat faces rear sprockets R1-R8 (the left side in FIG. 3), and the termlaterally outward refers to the side of the derailleur that faces awayfrom rear sprockets R1-R8 (the right side in FIG. 3).

Bicycle frame 14 is part of an overall bicycle frame that includes achain stay 26, a seat stay 30 and a frame end 34 (commonly referred toas a dropout) that joins chain stay 26 and seat stay 26 together,typically by welding chain stay 26 and seat stay 30 to frame end 34.Conceptually, each of these frame structures is well known. However,this embodiment employs a configuration of frame end 34 that differsfrom common frame ends. More specifically, frame end 34 comprises aforward portion 38 and a rearward portion 42, wherein forward portion 38extends from chain stay 26 and seat stay 30 to a horizontal positionaligned with rotational axis X, and rearward portion 42 extends from thehorizontal position aligned with rotational axis X rearward. A junctionbetween forward portion 38 and rearward portion 42 forms an axlereceiving slot 46 dimensioned to receive rear axle 22 therein. In thisembodiment, axle receiving slot 46 is oriented substantially verticalwith a slight incline and includes an open end 50 and a closed end 54,wherein open end 50 is disposed below closed end 54. Rearward portion 42extends rearward and downward at an incline and forms a derailleurattachment structure in the form of a laterally projecting annularmounting boss 58 with an opening 60 dimensioned to receive a derailleurmounting bolt 62 therein. Of course, in some embodiments mounting boss58 need no project laterally, in which case the surface of opening 60forms the derailleur attachment structure. In this embodiment, opening60 may be located from approximately 180° to approximately 240° relativeto rotational axis X, or, to facilitate measurement independently ofaxle 22, from approximately 180° to approximately 240° relative toclosed end 54 of axle receiving slot 46. Rearward portion 42 of frameend 34 extends further rearward from mounting boss 58 to form a positionsetting abutment 66 that functions in a manner discussed below.

Derailleur 10 comprises a base member 70, a movable member 74 thatsupports a chain guide 78, and a linking mechanism 82 coupled betweenbase member 70 and movable member 74 so that chain guide 78 moveslaterally relative to base member 70. As best seen in FIGS. 2 and 3,base member 70 comprises an annular mounting boss 86 with a mountingsurface 90 that faces laterally outward to face mounting boss 58 onframe end 34 and an inner surface 92, opposite mounting surface 90, thatfaces laterally inward and has an inner base member plane BMP, atransition portion 94 that extends rearward and downward at an inclinefrom mounting boss 86, and a link coupling portion 98 disposed at alower end portion of extension portion 94.

As best seen in FIGS. 1 and 3, an adjuster mounting boss 99 extendsrearward and then laterally outward from mounting boss 86. A laterallyouter portion of adjuster mounting boss 99 includes an adjuster mountingstructure in the form a threaded opening 100 dimensioned to threadinglyengage an adjuster in the form of an adjusting screw 101. The tip ofadjusting screw 101 abuts against position setting abutment 66 on frameend 34. Thus, the rotational position between frame end 34 and basemember 70 may be adjusted simply by rotating adjusting screw 101.

An outer casing coupler 102 in the form of a hollow cylinder is disposedon an upper portion of transition portion 94, wherein outer casingcoupler 102 is dimensioned to couple to and terminate an outer casing106 of a Bowden cable 110 in a known manner. Outer casing coupler 102 ispositioned to be located rearward from rotational axis X and, moreparticularly, rearward from frame end 34 and at least partiallylaterally inward from mounting surface 90 of base member 70 as shown inFIG. 3. Outer casing coupler 102 includes an outer casing receiving bore104 having a bore axis B that is inclined relative to a pulley plane Pdescribed below. If desired, a cable adjusting bolt (not shown), theconcept and structures of which are well known, may be mounted in outercasing receiving bore 104 so as to be disposed between outer casingcoupler 102 and outer casing 106.

As shown in FIGS. 1 and 2, link coupling portion 98 includes a supportwall 114, an outer link mounting ear 118 and an inner link mounting ear122. In this embodiment, inner link mounting ear 122 is formed as anextension of transition portion 94 that inclines laterally inwardly fromfront to rear and from top to bottom, support wall 114 extends laterallyoutwardly from inner mounting ear 122 so as to incline rearwardly fromtop to bottom and from transition portion 94 to the laterally outer end,and outer link mounting ear 118 extends downwardly from support wall 114so as to incline laterally inwardly from front to rear and from top tobottom.

Movable member 74 comprises a main body 130 and a link mounting frame134. In this embodiment, main body 130 comprises a generally cylindricalmember that houses a torsion coil spring 138, one end of which isinserted into a spring mounting opening 142 formed in a laterally outerside wall 146 of main body 130. Link mounting frame 134 comprises anupper link mounting boss 150, a lower link mounting boss 154, and anupper chain guide link mounting frame 158, all of which are formed asone piece with main body 130.

Linking mechanism 82 comprises linking members in the form of alaterally outer upper link 162 and a laterally inner lower link 166. Afirst end of upper link 162 is straddled by link coupling portion 98 ofbase member 70 and is pivotably connected thereto by a pivot shaft 170that defines a pivot axis P1. The second end of upper link 162 is forkedto straddle upper link mounting boss 150 of link mounting frame 134 ofmovable member 74 and is pivotably connected thereto by a pivot shaft174 that defines a pivot axis P2. Because of this arrangement, adistance between the outermost edges of the first end of upper link 162at base member 70 is less than a distance between the outermost edges ofthe second end of upper link 162 at movable member 74. An outer limitadjusting screw 186 and an inner limit adjusting screw 190 are mountedon upper link 162 to adjust the laterally outermost and laterallyinnermost positions of movable member 74, respectively, in a well knownmanner.

Similarly, a first end of lower link 166 is straddled by link couplingportion 98 of base member 70 and is pivotably connected thereto by apivot shaft 178 that defines a pivot axis P3. An actuating arm 175extends downwardly and laterally inwardly from the first end of lowerlink 166 so as to generally conform to the inclined contour formed bythe outer peripheral surfaces of the plurality of sprockets R1-R8. Acable attachment structure in the form of a bolt 176 and a clampingwasher 177 is provided at the outer end of actuating arm 175 to attach ashift control cable such as an inner cable 108 of Bowden cable 106, forexample, as shown in FIG. 2. As shown in FIG. 3, bolt 176 and washer 177are disposed laterally inward from mounting surface 90 of base member 70when chain guide 78 is located at a laterally outermost position.

Lower link 166 is forked beginning in close proximity to pivot shaft 178to form legs 179 and 180 (FIG. 2) that extend toward movable member 74.Legs 179 and 180 straddle lower link mounting boss 154 of link mountingframe 134 of movable member 74 and is pivotably connected thereto by apivot shaft 182 (FIG. 1) that defines a pivot axis P4. Because of thisarrangement, a distance between the outermost edges of the first end oflower link 166 at base member 70 is less than a distance between theoutermost edges of the second end of lower link 166 at movable member74.

As shown in FIG. 2, legs 179 and 180 of lower link 166 receive a coiledreturn spring 181 therebetween. One end of spring 181 is connected tobase member 70 at pivot shaft 170, and the other end of spring 181 isconnected to movable member 74 at pivot shaft 182. As a result, spring181 biases movable member 74 laterally outwardly.

Chain guide 78 comprises an upper chain guide link 194, a first or upperguide pulley 198 rotatably mounted to upper chain guide link 194 througha pivot shaft 200, a lower chain guide link 202, and a second or lowertension pulley 206 rotatably mounted to lower chain guide link 202through a pivot shaft 208. Upper chain guide link 194 is pivotablyconnected to upper chain guide link mounting frame 158 through a pivotshaft 210. Upper chain guide link 194 comprises a chain pushing member214 and a chain regulating unit 218. Chain pushing member 214 isdisposed between upper chain guide link mounting frame 158 and guidepulley 198, with an arcuate portion 222 disposed in close proximity tothe teeth on guide pulley 198. Chain pushing member 214 is provided topush chain 18 when switching chain 18 from a smaller diameter sprocketto a larger diameter sprocket and to prevent chain 18 from derailingfrom guide pulley 198. Chain pushing member 214 rotates around a chainpushing member rotational axis defined by pivot shaft 210, which in thisembodiment is offset from a first pulley axis defined by pivot shaft200. As a result, both guide pulley 198 and chain pushing member 214rotate around the chain pushing member rotational axis defined by pivotshaft 210.

Chain regulating unit 218 comprises an inner plate 226, an outer plate230 and a regulator pin 234. A radially inner end of inner plate 226 iscoupled to pivot shaft 200, and a radially outer end of inner plate 226is fastened to one end of regulator pin 234. A radially inner portion ofouter plate 230 joins with chain pushing member 214 and is coupled topivot shaft 210, and a radially outer end of outer plate 230 is fastenedto the other end of regulator pin 234. Inner plate 226 helps to preventchain 18 from derailing from guide pulley 198 when switching chain 18from a larger diameter sprocket to a smaller diameter sprocket, andouter plate 230 helps to prevent chain 18 from derailing from guidepulley 198 when switching chain 18 from a smaller diameter sprocket to alarger diameter sprocket. Regulator pin 234 helps to prevent excessiveradial movement of chain 18 and ensures that upper chain guide link 194rotates counterclockwise around pivot shaft 210 in response to forwardswinging of chain 18. However, chain regulating unit 218 may be omittedin some embodiments.

As shown in FIG. 2, an upper end 205 of lower chain guide link 202 ispivotably coupled to main body 130 of movable member 74 through a pivotshaft 238 and includes a plurality of, e.g., three spring couplingopenings 242. The other end of spring 138 mentioned above is insertedinto one of the spring coupling openings 242 to set a desired biasingforce on lower chain guide link 202. As a result, lower chain guide link202 is biased clockwise in FIG. 1. A lower end 207 of lower chain guidelink 202 rotatably supports tension pulley 206 through pivot shaft 208and nonrotatably supports a chain regulating unit 248. In thisembodiment, as shown in FIG. 4, upper end 205 is substantiallyvertically straight and is laterally inwardly offset relative to lowerend 207, which also is substantially vertically straight. As with chainregulating unit 218, chain regulating unit 248 comprises an inner plate252, an outer plate 256 and a regulator pin 260. A radially inner end ofinner plate 252 is coupled to pivot shaft 208, and a radially outer endof inner plate 252 is fastened to one end of regulator pin 260. In thisembodiment, outer plate 256 is formed as a part of lower chain guidelink 202 and supports pivot shaft 208. A radially outer end of outerplate 256 is fastened to the other end of regulator pin 260. Inner plate252 helps to prevent chain 18 from derailing from tension pulley 206when switching chain 18 from a larger diameter sprocket to a smallerdiameter sprocket, and outer plate 256 helps to prevent chain 18 fromderailing from tension pulley 206 when switching chain 18 from a smallerdiameter sprocket to a larger diameter sprocket. Regulator pin 260 helpsto prevent excessive radial movement of chain 18. Chain regulating unit248 may be omitted in some embodiments.

In this embodiment, base member 70, movable member 74, chain guide 78and linking mechanism 82 are dimensioned so that guide pulley 198 islocated at a range of from approximately 220° to approximately 270°relative to rotational axis X when chain guide 78 is disposed in thelaterally outermost position.

As shown in FIG. 4, guide pulley 198 has a pulley plane P that bisectsguide pulley 198. In this embodiment, each tooth on guide pulley 198 issymmetrical and centered on the pulley when viewed perpendicular topivot shaft 200 so that pulley plane P is located in the center of guidepulley 198, and all of the pulley teeth lie in pulley plane P. In thisembodiment, pulley plane P also bisects tension pulley 206. In order toprovide a decreased laterally outward profile for derailleur 10, thecomponents are structured so that pulley plane P intersects at least oneof upper link 162 or lower link 166 when chain guide 78 is disposed in aposition somewhere between a laterally outermost rest position and alaterally innermost position (such as the laterally outermost positionshown in FIG. 4).

As used throughout herein, the word “intersect” has the ordinary meaningof having one or more points in common. Thus, the term also includes,for example, a tangent relationship. The laterally outermost positionmay be the laterally outermost position when derailleur 10 is removedfrom the bicycle. In this case, the laterally outermost position may bedetermined by the position of chain guide 78 with the derailleur at restand subjected only to the biasing force of return spring 181, and thelaterally innermost position is determined by the position of chainguide 78 when chain guide 78 is manually pulled to its laterallyinnermost position. Alternatively, the laterally outermost position maybe determined by the position of chain guide 78 when it is set to bealigned with the smallest diameter rear sprocket R1, and the laterallyinnermost position may be determined by the position of chain guide 78when it is set to be aligned with the largest diameter rear sprocket R8.The word “between” is used in an inclusive sense.

Furthermore, in this embodiment, pulley plane P intersects at least oneof pivot axis P1 or pivot axis P3 when measured across all components atthe coupling when chain guide 78 is disposed in a position somewherebetween a laterally outermost rest position and a laterally innermostposition (such as the laterally outermost position shown in FIG. 6). Forexample, pivot shaft 170 defines pivot axis P1 and couples upper link162 to base member 70. The laterally outer tip of pivot shaft 170 isexposed at outer link mounting member 118, whereas the laterally innertip of pivot shaft 170 is inserted into a blind bore (not shown) ininner link mounting member 122 so that the inner lateral tip is notexposed at inner link mounting member 122. The length of pivot axis P1measured across all components at the coupling therefore extends fromthe laterally outer tip of pivot shaft 170 at pivot axis P1 to thelaterally inner surface of inner link mounting member 122 at pivot axisP1. Similarly, pivot shaft 178 defines pivot axis P3 and couples lowerlink 166 to base member 70. The laterally outer tip of pivot shaft 178is exposed at outer link mounting member 118, whereas the laterallyinner tip of pivot shaft 178 is inserted into a blind bore (not shown)in inner link mounting member 122 so that the inner lateral tip is notexposed at inner link mounting member 122. The length of pivot axis P3measured across all components at the coupling therefore extends fromthe laterally outer tip of pivot shaft 178 at pivot axis P3 to thelaterally inner surface of inner link mounting member 122 at pivot axisP3.

In this embodiment, pulley plane P intersects both upper link 162 andlower link 166 as well as pivot axes P1 and P3 when chain guide 78 isdisposed in a position somewhere between the laterally outermostposition and the laterally innermost position, such as the laterallyoutermost position shown in FIG. 4. However, it is not necessary tointersect all recited components at all lateral positions of chain guide78. For example, while at least one of pivot axes P1-P4 is disposed on alaterally inner side of pulley plane P, and at least one of pivot axesP1-P4 is disposed on a laterally outer side of pulley plane P, in thisembodiment second pivot axis P2 as measured according to the definitionabove is disposed entirely on the laterally outer side of pulley plane P(as well as movable member plane M) in the position shown in FIG. 3. Inthis embodiment, pulley plane P intersects a space S1 between any facingsurfaces (e.g., surfaces 261 and 262 shown in FIG. 2) of upper link 162and lower link 166 as shown in FIG. 4. Pulley plane P also intersectsbase member 70 when chain guide 78 is disposed in a position somewherebetween the laterally outermost position and the laterally innermostposition, such as the laterally outermost position shown in FIG. 3.

As shown further in FIG. 4 (with spring 181 removed for clarity), amovable member plane M that is substantially parallel to pulley plane Pintersects an innermost surface 264 of movable member 74. In thisembodiment, innermost surface 264 is coplanar with movable member planeM, although other configurations are possible since movable member 74may have many different shapes. Movable member plane M intersects bothupper link 162 and lower link 166, pivot axes P1 and P3, and the spaceS1 between facing surfaces of upper link 162 and lower link 16 whenchain guide 78 is disposed in a position somewhere between the laterallyoutermost position and the laterally innermost position. Furthermore, atleast a portion of a space S2 between movable member plane M and pulleyplane P intersects the space S1 between facing surfaces of upper link162 and lower link 16 when chain guide 78 is disposed in a positionsomewhere between the laterally outermost position and the laterallyinnermost position, such as the laterally outermost position shown inFIG. 4.

As shown in FIGS. 3 and 8, derailleur 10 has a very low lateral profile.For example, when chain guide 78 is located in the laterally outermostposition shown in FIG. 3, the components barely protrude laterallyoutward relative to frame 14. Actuating arm 175 and portions of linkagemechanism 82 are disposed laterally inward from pulley plane P andmovable member plane M and follow the diagonal contour of sprocketsR1-R8, thereby forming a very compact structure. When chain guide 78 islocated in the laterally innermost position shown in FIG. 8, mountingboss 58 is the laterally outermost portion of derailleur 10. In fact,mounting boss 58 does not even protrude laterally outward relative tochain stay 26 or seat stay 30. In this position, actuating arm 175 andlinkage mechanism 82 again following the diagonal contour of sprocketsR1-R8.

Prior art derailleurs do not have the ability to have such a lowprofile. One reason is that the chain guide in prior art derailleurs hasa chain pushing member that is formed as one piece with an inner platethat extends from the upper guide pulley to the lower tension pulley,and this inner plate limits the ability of the chain guide to movelaterally outwardly. In the presently disclosed embodiment, chainpushing member 214 is dimensioned to as not to interfere with theability of chain guide 78 to move laterally outwardly. The two-piecestructure of chain guide 78 further facilitates such lateral movement.Furthermore, the base member and linking mechanism in prior artderailleurs are dimensioned to be mounted substantially below, or evenin front of, the rotational axis X of the rear wheel, and this requiressufficient lateral spacing to ensure that the linking mechanism does notstrike the sprockets during operation. Since base member 70, upper link162, lower link 166 movable member 74 and chain guide 78 in thepresently disclosed embodiment are dimensioned so that guide pulley 198is located at a range of from approximately 220° to approximately 270°relative to rotational axis X when chain guide 78 is disposed in thelaterally outermost position, the lateral distance required for thecomponents further decreases because the linking mechanism is able tomore closely follow the contour formed by the outer peripheral surfacesof the plurality of sprockets R1-R8. Of course, while many of thefeatures described herein contribute to a markedly low profilederailleur, not all features are required, depending upon theapplication.

FIG. 12 is a laterally outer view of rear derailleur 10 mounted to aframe end 300 of a conventional frame 14′. In this case, frame end 300comprises a forward portion 304 and a rearward portion 308, whereinforward portion 304 extends from chain stay 26 and seat stay 30 to ahorizontal position aligned with rotational axis X, and rearward portion308 extends from a horizontal position aligned with rotational axis Xrearwardly and substantially vertically downwardly. A junction betweenforward portion 304 and rearward portion 308 forms an axle receivingslot 312 dimensioned to receive rear axle 22 therein. In thisembodiment, axle receiving slot 312 again is oriented substantiallyvertically with a slight incline and defines an open end 316 and aclosed end 320, wherein open end 316 is disposed below closed end 320.Rearward portion 308 forms an annular mounting boss 324 with an opening(not shown) dimensioned to receive a mounting bolt 328 therein.

Derailleur 10 is mounted to an extension member 330 having a first endportion 334 and a second end portion 338, wherein first end portion 334includes a mounting opening 342 dimensioned for receiving mounting bolt346 therein. Second end portion 338 includes a derailleur attachmentstructure in the form of a derailleur mounting opening 350 dimensionedfor receiving mounting bolt 62 therethrough. Extension member 330 isdimensioned such that, when extension member 330 is attached to frameend 300, mounting opening 350, and hence boss member 86 of base member70 of derailleur 10, is located from approximately 180° to approximately240° relative to axle receiving opening 312, from approximately 180° toapproximately 240° relative to rotational axis X, or, to facilitatemeasurement independently of axle 22, from approximately 180° toapproximately 240° relative to closed end 320 of axle receiving opening312. Rearward portion 38 extends further rearwardly from derailleurmounting opening 350 to form a position setting abutment 354 thatfunctions in the same manner as position setting abutment 66 in thefirst embodiment.

FIG. 13 is a laterally outer view of another embodiment of a rearderailleur 10′ attached to frame end 300 of conventional frame 14′. Rearderailleur 10′ has the features described for derailleur 10 in FIG. 12except for a different extension member 330′ and a modified base member70′ that supports a cable guide unit 400. Also, in this embodiment chainguide 78 is biased toward the largest rear sprocket R8 (by switching theends of return spring 181 to pivot shafts 174 and 178), so inner cable108 is attached to a cable clamp 404 fixed to upper link 162.

Extension member 330′ has a first end portion 334 and a modified secondend portion 338′, wherein first end portion 334 includes mountingopening 342 dimensioned for receiving mounting bolt 346 therein. Secondend portion 338′ includes a derailleur attachment structure in the formof a derailleur mounting boss 408 (FIGS. 15 and 16) dimensioned forsupporting base member 70′. Extension member 330′ is dimensioned suchthat, when extension member 330′ is attached to frame end 300,derailleur mounting boss 408, and hence base member 70′, is located fromapproximately 180° to approximately 240° relative to axle receivingopening 312, from approximately 180° to approximately 240° relative torotational axis X, or from approximately 180° to approximately 240°relative to closed end 320 of axle receiving opening 312.

As shown more clearly in FIG. 16, derailleur mounting boss 408 includesan inner end face 444, an outer end face 445, and a step-shaped outerperipheral surface 446 extending between end faces 444 and 445. Endfaces 444 and 445 are axially opposed, with inner end face 444 forming aportion of the inner side of extension member 330′. Outer end face 445has a centrally located threaded fastener opening 449 and three axiallyextending projections 450. Fastener opening 449 is arranged andconfigured to receive a fixing bolt 451 (FIG. 15) for attaching cableguide unit 400 in a non-rotatable manner. Projections 450 are generallyarc-shaped members arranged on an imaginary circle that is coaxiallyarranged relative to fastener opening 449. Outer peripheral surface 446comprises four outer peripheral surfaces 452, 453, 454 and 455 withprogressively decreasing diameters. Three axially outwardly facing endsurfaces 456, 457 and 458 are disposed between adjacent pairs of outerperipheral surfaces 452, 453, 454 and 455. A stopper member 448 isdisposed at the lower portion of outer peripheral surface 452.

As shown in FIG. 17, base member 70′ comprises a tubular mountingportion 462, a cable guide channel 461, and a linkage attachment portion464. In this embodiment, mounting portion 462, cable guide channel 461,and linkage attachment portion 464 are integrally formed as a one-piece,unitary member from a hard, rigid material such as a lightweight metal(e.g. aluminum alloy). As shown in FIG. 15, mounting portion 462 iscoaxially mounted on derailleur mounting boss 408 for rotation around abase member axis B. Cable guide channel 461 projects from linkageattachment portion 464 and has a through bore 461 a configured andarranged to receive inner cable 108 therethrough. Through bore 461 a hasa center axis that is arranged substantially perpendicular to basemember axis B. Linkage attachment portion 464 is a generally U-shapedmember that has a pair of mounting flanges 464 a and 464 b with pivotshaft holes for attaching upper and lower links 162 and 166 with pivotshafts 170 and 178.

Mounting portion 462 of base member 70′ comprises a first cylindricalsection 468, a second cylindrical section 469, a third cylindricalsection 470, and an end wall 473 that extends radially inwardly fromfirst cylindrical section 468 and connects first cylindrical section 468to second cylindrical section 469 and third cylindrical section 470. Anaxially extending abutment projection 462 a is disposed at the axiallyinner end of first cylindrical section 468 for contacting stopper member448 on derailleur mounting boss 408. When mounting portion 462 ismounted to derailleur mounting boss 408 as shown in FIG. 15, the innerperipheral surface of the axially inner end portion of first cylindricalsection 468 contacts outer peripheral surface 453 of derailleur mountingboss 408, the inner peripheral surface of second cylindrical section 469contacts outer peripheral surface 455, and an annular space is formedbetween the inner peripheral surface of first cylindrical section 468and outer peripheral surface 454. Preferably, a metal bushing 480 isdisposed in third cylindrical section 470 for contacting outerperipheral surface 455.

A biasing element in the form of a torsion spring 442 is disposed aroundouter peripheral surface 454 of derailleur mounting boss 408. Spring 442has a first end 482 and a second end 483, wherein first end 482 isfitted within an opening 459 formed in end face 457 of derailleurmounting boss 408, and second end 483 is fitted within an opening 460formed in end wall 473 of mounting portion 462 of base member 70′.Openings 459 and 460 are circumferentially oriented relative to eachother to provide a counterclockwise biasing force to base member 70′.

Cable guide unit 400 comprises a cable guide mounting member 490, acable guide in the form of a cable guide roller 491, and a fastener 492.Cable guide mounting member 490 includes an unthreaded opening 497 forreceiving bolt 451, an unthreaded opening 499 for receiving fastener492, a threaded opening 500 for threadingly engaging fastener 492, threearcuate recesses 498 for engaging the three arcuate projections 450 onderailleur mounting boss 408, and an outer casing receiving recess 496for receiving outer casing 106 of Bowden cable 110 therein. When fixingbolt 451 is passed through opening 497 in cable guide mounting member490 and screwed into fastener opening 449 with projections 450 disposedin recesses 498, cable guide mounting member 490 is nonrotatably securedto derailleur mounting boss 408.

Cable guide roller 491 includes a wire guide groove 491 a and a tubularbearing 491 b fitted within an opening 491 c. When fastener 492 ispassed through opening 499 in cable guide mounting member 490 andthrough tubular bearing 491 b and is screwed into threaded opening 500,cable guide roller 491 is mounted to cable guide mounting member 490 forrotation around a cable guide axis C that is substantially parallel toand offset from base member axis B. As shown in FIG. 14 wire guidegroove 491 a intersects a pivot area A defined by opening 497 inderailleur mounting boss 408 when viewed in a direction along basemember axis B.

As shown more clearly in FIG. 14, outer casing receiving recess 496 hasa step-shaped configuration with its center axis aligned with wiregroove 491 a of cable guide roller 491. Outer casing receiving recess496 is configured and arranged to contact the end of outer casing 106 sothat inner cable 108 extends out of outer casing 106, through the smallportion of the outer casing receiving recess 496, and around a portionof the perimeter of cable guide roller 491. Inner cable then exits cableguide roller 491 and is attached to cable clamp 404 on upper link 162.

It should be readily apparent that derailleur mounting boss 408 andcable guide mounting member 490 of cable guide unit 400 are stationary(non-movable) relative to extension member 330′ and frame 14′. On theother hand, base member 70′ is rotatably mounted on derailleur mountingboss 408 so that base member 70′, linking mechanism 82, movable member74 and chain guide 78 all move together about base member axis B. Sincewire guide groove 491 a intersects the pivot area A defined by opening497 in derailleur mounting boss 408 when viewed in a direction alongbase member axis B, inner cable 110 is not pulled when base member 70′rotates around base member axis B. This prevents unwanted lateralmovement of movable member 74 and chain guide 78 during such rotation.

While the above is a description of various embodiments of inventivefeatures, further modifications may be employed without departing fromthe spirit and scope of the present invention. For example, the size,shape, location or orientation of the various components may be changedas desired. Components that are shown directly connected or contactingeach other may have intermediate structures disposed between them. Thefunctions of one element may be performed by two, and vice versa. Thefunction of one element may be performed by another, and functions maybe interchanged among the elements. The structures and functions of oneembodiment may be adopted in another embodiment. It is not necessary forall advantages to be present in a particular embodiment at the sametime. Every feature which is unique from the prior art, alone or incombination with other features, also should be considered a separatedescription of further inventions by the applicant, including thestructural and/or functional concepts embodied by such feature(s). Thus,the scope of the invention should not be limited by the specificstructures disclosed or the apparent initial focus or emphasis on aparticular structure or feature.

1. A bicycle rear derailleur comprising: a base member including: abicycle mounting portion for attaching to a bicycle frame member,wherein the bicycle mounting portion has a laterally inwardly facingsurface and a laterally outwardly facing surface opposite the laterallyinwardly facing surface, wherein at least one of the laterally inwardlyfacing surface or the laterally outwardly facing surface is adapted toface the bicycle frame member when the bicycle mounting portion isattached to the bicycle frame member, wherein the laterally inwardlyfacing surface forms an inner base member plane; and a link couplingportion; wherein at least a portion of the link coupling portion isdisposed laterally inwardly of the inner base member plane; a movablemember that supports a chain guide including a first pulley that rotatesaround a first pulley axis, wherein the pulley has a pulley plane thatis substantially perpendicular to the first pulley axis and bisects thepulley; a first linking member pivotably coupled to the link couplingportion of the base member for pivoting around a first pivot axis thatintersects the inner base member plane and pivotably coupled to themovable member for pivoting around a second pivot axis so that the chainguide moves laterally relative to the base member between a firstlateral position and a second lateral position; wherein, when thederailleur is viewed perpendicular to the first pulley axis such thatthe first pulley axis is horizontal and the pulley plane is vertical, atleast one of the first pivot axis or the second pivot axis is verticallyinclined relative to the pulley plane so that, when the derailleur isviewed from laterally outwardly of the derailleur along the first pulleyaxis such that the first pulley axis is disposed below and to the rightof the base member, the first pulley is located in a laterally outwardupper position when the chain guide is in the first position, and thefirst pulley is located in a laterally inward lower position when thechain guide is in the second lateral position; and a cable guidestructured to guide a shift control cable; wherein the pulley planeintersects the first linking member when the chain guide is located at afirst position between the first lateral position and the second lateralposition.
 2. The derailleur according to claim 1 wherein the base memberis structured to be mounted relative to a bicycle frame for rotationaround a base member axis.
 3. The derailleur according to claim 2further comprising a biasing element for biasing the base member in aselected rotational direction around the base member axis.
 4. Thederailleur according to claim 1 wherein the cable guide is structured tochange a direction of the shift control cable.
 5. The derailleuraccording to claim 4 wherein the cable guide rotates relative to thebase member.
 6. The derailleur according to claim 5 wherein the cableguide comprises a cable guide roller that rotates around a cable guideaxis.
 7. The derailleur according to claim 6 wherein the base member isstructured to be mounted relative to a bicycle frame for rotation arounda base member axis.
 8. The derailleur according to claim 7 wherein thecable guide axis is substantially parallel to the base member axis. 9.The derailleur according to claim 8 wherein the cable guide axis isoffset from the base member axis.
 10. The derailleur according to claim1 further comprising a mounting member for mounting to a bicycle frame,wherein the base member is supported to the mounting member.
 11. Thederailleur according to claim 10 wherein the cable guide is mounted tothe mounting member.
 12. The derailleur according to claim 11 whereinthe cable guide rotates relative to the mounting member around a cableguide axis.
 13. The derailleur according to claim 12 wherein the basemember is mounted to the mounting member for rotation around a basemember axis.
 14. The derailleur according to claim 13 wherein the cableguide axis is substantially parallel to the base member axis.
 15. Thederailleur according to claim 14 wherein the cable guide axis is offsetfrom the base member axis.
 16. The derailleur according to claim 13further comprising a cable guide mounting member immovably coupled tothe mounting member, wherein the cable guide is rotatably mounted to thecable guide mounting member.
 17. The derailleur according to claim 16wherein the cable guide comprises a cable guide roller that rotatesaround a cable guide axis.
 18. The derailleur according to claim 17further comprising a biasing element for biasing the base member in aselected rotational direction relative to the mounting member.
 19. Thederailleur according to claim 18 wherein the mounting member comprisesan elongated extension member, wherein the extension member is elongatedsubstantially horizontally.
 20. The derailleur according to claim 19wherein the mounting member is structured to be mounted directly to thebicycle frame.
 21. The derailleur according to claim 1 wherein at leastone of the first pivot axis or the second pivot axis extends from alaterally inner upper location to a laterally outer lower location. 22.A bicycle rear derailleur comprising: a base member having a base membermounting opening for receiving a fastener therein for attaching the basemember to a bicycle frame member; a movable member that supports a chainguide including a first pulley that rotates around a first pulley axis,wherein the pulley has a pulley plane that is substantiallyperpendicular to the first pulley axis and bisects the pulley; a firstlinking member pivotably coupled to the base member for pivoting arounda first pivot axis and pivotably coupled to the movable member forpivoting around a second pivot axis so that the chain guide moveslaterally relative to the base member between a first lateral positionand a second lateral position; a second linking member pivotably coupledto the base member for pivoting around a third pivot axis and pivotablycoupled to the movable member for pivoting around a fourth pivot axis;wherein, when the derailleur is viewed from the rear of the derailleurperpendicular to the first pulley axis and along the pulley plane suchthat the first pulley axis is horizontal and the pulley plane isvertical, and such that both the first pivot axis and the third pivotaxis are disposed at their lowermost position relative to the basemember mounting opening, at least one of the first pivot axis or thesecond pivot axis is vertically inclined relative to the pulley planefrom a laterally inner upper location to a laterally outer lowerlocation so that, when the derailleur is viewed from laterally outwardlyof the derailleur along the first pulley axis such that the first pulleyaxis is disposed below and to the right of the base member, the firstpulley is located in a laterally outward upper position when the chainguide is in the first position, and the first pulley is located in alaterally inward lower position when the chain guide is in the secondlateral position; and a cable guide structured to guide a shift controlcable; wherein the pulley plane intersects the first linking member whenthe chain guide is located at a first position between the first lateralposition and the second lateral position.
 23. The derailleur accordingto claim 22 wherein the first linking member is pivotably coupled to thebase member through a first linking member pivot shaft, wherein thesecond linking member is pivotably coupled to the base member through asecond linking member pivot shaft, and wherein, when the derailleur isviewed from the rear of the derailleur perpendicular to the first pulleyaxis and along the pulley plane such that the first pulley axis ishorizontal and the pulley plane is vertical, and such that both thefirst linking member pivot shaft and the second linking member pivotshaft are disposed at their lowermost position relative to the basemember mounting opening, at least one of the first linking member pivotshaft or the second linking member pivot shaft is vertically inclinedrelative to the pulley plane from a laterally inner upper location to alaterally outer lower location.